1. Field of the Invention
This invention relates to an air conditioning waste heat/reheat method and apparatus and, more particularly, to a method and apparatus for utilizing heat from the post compressor and/or post condenser region of a refrigeration cycle to heat a working fluid to provide a reheating of the air leaving the evaporator.
2. Description of the Background Art
In the field of air conditioning systems, a working fluid capable of changing state under different conditions of a temperature and pressure is utilized for accepting and giving up heat energy in a specific sequence. The working fluid may be Freon, alcohol or similar fluid. In a conventional air conditioning system, the working fluid moves in a cycle of operation between an evaporator, compressor and condenser. The evaporator is generally inside the building to be cooled. At the evaporator, the working fluid is converted from a liquid at about 90 degrees Fahrenheit to a gas at about 45 degrees Fahrenheit for cooling air passing there adjacent. The working fluid then moves from the evaporator to the compressor. The compressor is normally outside and functions to compress the working fluid. The working fluid entering the compressor is a low temperature gas at about 65 degrees Fahrenheit and leaves as a high temperature gas at about 150 degrees Fahrenheit. Movement of the working fluid is then from the compressor to the condenser. The condenser, normally outside, functions to convert the received gas at about 150 degrees Fahrenheit to a liquid at about 90 degrees Fahrenheit.
In some air conditioning systems, the air moving through the evaporator is excessively cooled then reheated. It is standard practice in many applications to excessively cool the air moving through the evaporator taking it from about 80 degrees Fahrenheit to about 50 to 55 degrees Fahrenheit in order to dehumidify the air. Such cooling through the evaporator normally takes the air to a temperature which is cooler than desired for human comfort, but this low temperature is required to properly dehumidify the air. The evaporator, consequently, overcools the air and tends to ring out the moisture therefrom. A reheater must then be used to warm the air to a comfortable level for occupants of the conditioned space. This reheating also provides a lowering of the relative humidity of the overcooled air.
Limited efforts have been made in the past to reheat the post evaporator air to make such air more comfortable for occupants of the air conditioned building. Efforts in the past have also been directed to utilizing the heating of the air at a reheater for cooling various parts of the conventional air conditioning system. Such cooling, to a limited degree, has been through heat-pipe technology. Nothing in the prior art, however, suggests the utilizing of heat-pipe technology for reheating in combination with post compressor and/or post condenser refrigerant cooling without cutting into the existing air conditioning system. By way of example, U.S. Pat. No. 2,111,618 to Erbach and 2,291,029 to Everett disclose the utilization of heat-pipe technology post evaporator for post compressor cooling of the working fluid. These patents are deficient because they require that the primary refrigerant lines be cut into. This requires delicate handling of the refrigerant under the new laws to preclude dispensing of refrigerant to the atmosphere. The refrigerant must be pumped out, the lines are then cut, then resoldered, then pumped out to create a vacuum and finally the refrigerant is reintroduced. Additionally, the reheaters are of an inferior design for the heat-pipe process.
Heat-pipe technology is also utilized in U.S. Pat. Nos. 2,214,057 to Hall; 4,607,498 to Dinh and 4,971,139 to Khattar. In these references, however, the heat-pipe technology is used to transfer heat from return air to supply air. These patents are deficient since these heat-pipes introduce significant pressure drops in the air stream which require additional fan horsepower to overcome. Additionally, these heat-pipes block the access to the cooling coil thereby complicating maintenance and cleaning. Finally these heat-pipes perform their function only when the conventional air conditioning system is in operation. Under seasonal conditions of low heat loads (i.e. fall and spring), the conventional air conditioning system does not operate and no dehumidification is performed.
A third body of art as exemplified by U.S. Pat. Nos. 1,837,798 to Shiplee; 2,154,136 to Parcaro; 2,734,348 to Wright; 2,932,178 to Armstrong; 3,026,687 to Robson and 3,123,492 to McGrath. These patents all use nonheat-pipe technology for transferring heat in an air conditioning system from one location to another but require supplemental utilization to effect the secondary flow of fluids. These patents are deficient since in these patents, difficulties can arise in balancing the refrigerant charge of the primary system. They all contain numerous moving parts such as two-, three- and four-way valves, pumps and controls all of which create a complicated system with a high probability of malfunction.
None of the prior art inventions disclose the utilization of heat-pipe technology for minimum supplemental energy requirements to transfer the heat to the post evaporator position from the post compressor and/or post condenser locations for maximizing the efficiency of the system. The present invention effects its objects and advantages with minimum cost and utilizes only readily available materials in system configuration for retrofitting air conditioning systems without cut-ins or can be used for the generation of a most efficient air conditioning system through the application of the methods and apparatus of the present invention.
Therefore, it is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the air conditioning art.
Accordingly, it is the object of this invention to provide an improved air conditioning method and apparatus comprising a compressor, condenser and evaporator with lines in a primary loop for moving a working fluid in a continuous and automatic cycle of operation between such components; a first reheater located subsequent to the evaporator for heating the post evaporator air with a first supplemental loop coupling the first reheater to the post condenser line; a second reheater located subsequent to the first reheater with a second supplemental loop coupled with the post compressor lines; a valve in the first supplemental loop controlled by a humidistat; and a valve in the second supplemental loop controlled by a thermostat.
It is a further object of the present invention to improve indoor air quality by abating microbiological contaminants enhancing human comfort.
It is a further object of this invention to utilize post evaporator reheat energy to cool an air conditioning refrigerant at a post condenser location.
It is a further object of the present invention to utilize post evaporator reheat energy to cool a conventional air conditioning refrigerant at a post compressor location.
It is a further object of the present invention to use plural post evaporator reheat energies to cool the refrigerant of a conventional air conditioning system at both the post compressor and post condenser locations.
It is a further object of the present invention to cool refrigerant of a conventional air conditioning system without the disruption or cutting-in to the existing air conditioning system.
It is a further object of the present invention to use headered/finned pipes as the reheater of an air conditioning system for maximizing heat transfer and energy utilization for cooling at post compressor and post condenser locations.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiments in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.